In recent years, vehicles have been configured with new driver ignition interfaces to ease vehicle operation. For example, previous key-based interfaces have been replaced with keyless or smart-key interfaces. While previous key-based interfaces would require the operator to start or stop the engine by inserting or removing a key (e.g. an active key) from the ignition system, newer interfaces may allow the engine to be started or shutdown by pressing a start/stop button and/or based on the presence of a passive key (e.g., a smart key or electronic key fob) within a predetermined distance of the vehicle.
In the absence of a physical apparatus (e.g., an active key) that needs to be inserted/removed into the ignition system to start/stop the engine, a vehicle operator may unintentionally leave the vehicle with the engine idling. Recent advances in engine technology that have made vehicle engines quieter further increase the likelihood that a vehicle operator may leave the vehicle with the engine running. To address this issue, vehicle control systems may be configured to automatically shutdown an idling engine, for example, upon the elapse of a specified duration of idling time.
However, the inventors herein have identified potential issues in vehicles with such keyless interfaces. As an example, a vehicle operator may temporarily step out of the vehicle and intentionally leave the engine idling so as to maintain a desired cabin condition and ensure driving comfort upon return to the vehicle. This may be particularly important during inclement weather conditions. If the idling engine is prematurely stopped by the vehicle control system, the desired cabin condition may not be attained and the operator's drive feel may be degraded upon return to the vehicle.
In one example, the above issue may be at least partly addressed by a method of controlling a vehicle at standstill or stop. In one embodiment, the method comprises automatically inhibiting a shutdown of an idling engine based on each of a location of the vehicle and an ambient temperature condition. In this way, the automatic shutdown of an idling engine can be overridden during selected conditions, such as during cold weather conditions when the vehicle is parked outdoors.
In one example, a vehicle operator may have intentionally left a vehicle at standstill with the engine running. That is, the vehicle may be temporarily parked with the engine idling so as to warm the engine and the vehicle. A vehicle control system may use one or more of location sensors, on-board navigation equipment, temperature sensors, humidity sensors, oxygen sensors, etc., to determine the location of the vehicle, and to further determine whether the vehicle is located in a substantially enclosed space or an open space. For example, a controller may determine whether the vehicle is parked in a substantially enclosed space or an open space based on a change in an ambient condition (e.g., temperature or humidity), as estimated over a duration while the vehicle is at standstill. In response to the vehicle being parked in an open space, such as in an open parking lot, the vehicle control system may delay the automatic shutdown of the idling engine in anticipation of the operator returning to the vehicle imminently. The amount of delay may be based on environmental conditions, such as an ambient temperature of the location. For example, during cold weather conditions, the amount of delay may be increased to maintain a warm cabin temperature inside the vehicle or heat an emissions control device such as a catalyst. In comparison, in response to the vehicle being parked in a substantially enclosed space, such as an indoor garage, the vehicle control system may automatically shutdown the idling engine in anticipation of the operator not returning to the vehicle imminently.
In this way, by adjusting the shutdown of an idling vehicle engine based on the geographical location and environmental conditions of the vehicle, enhanced driver comfort can be provided, thereby improving the quality of the operator's drive feel. In addition, vehicle emissions and wasteful fuel consumption may be reduced.
It should be understood that the summary above is provided to introduce in simplified form a selection of concepts that are further described in the detailed description. It is not meant to identify key or essential features of the claimed subject matter, the scope of which is defined uniquely by the claims that follow the detailed description. Furthermore, the claimed subject matter is not limited to implementations that solve any disadvantages noted above or in any part of this disclosure.